Apparatus for forecasting and controlling atmospheric conditions in storage compartments



O. D. COLVIN Feb. 11, 1958 l APPARATUS FoR FoREcAsTING AND coNTRoLLING ATMOSPHERIC CONDITIONS IN-sToRAGE COMPARTMENTS 4 Sheets-Sheet' 1 Filed Oct. 12, 1955 Feb. 11, 1958 o. D. coLvlN 2,822,743

APPARATUS FOR FORECASTING AND CONTROLLING ATMOSPHERIC CONDITIONS IN STORAGE COMPARTMENTS 'Filed Oct. l2, 1955 4 Sheets-Sheet 2 Cmeso-DRY BULB EMPszA-rus (LoAoso WARM) WEA THE/z DRY BULB TEMPERATURE WEA THE/e Dew Ponvr TEMPERATURE Il Il DsHuM/o/r/E/e 4411? Dew Po/Nr EMPERATURE .S1-Aer WIr-Hour ./ok INVENTOR' 4 TRACK H' D'E TEMP* 1- H-OLD 4' SHIP SWEAT @0530 OL/VEED CULV/N v STAR-r DH. AT 00 v Y SAFE C; 1245Dnruvs v Bec/Ns.' l w'M-a mi 0'- n Feb. 11, 1958 O. D. COLVIN APPARATUS FOR FORECASTING AND CONTROLLING ATMO CONDITIONS IN STORAGE COMPARTMENTS4 S Filed 001'.. 12, 1955 IN V EN T 0R.

OL/ vs@ D. CoLv/N.

nited States Patent APPARATUS FOR FORECASTING AND CONTROL- LING ATMOSPHERIC CONDITIONS IN STORAGE COMPARTMENTS Oliver D. Colvin, Seattle, Wash. Application October 12, 1953, Serial No. 385,642 6 Claims. (Cl. 98-53) Because prevention by such advance remedial action requires substantially less energy and capacity than` cure after the event, the present invention achieves one of its primary objects of controlling such atmospheric conditions with relatively small: (a) expenditure of power and energy and (b) capacity requirement as compared to the prior art which has been largely concerned with cure alone. Thus the present invention also achieves another main aim of lower capital cost, expense, smaller size of apparatus, and greater ease of installation as compared to prior These objects and advantages are particularly important with respect to ships where space is at a premium and en-V ergy from the ships power plant is carefully rationed.

The invention provides, upon a common surface and with reference to `a common graph having a single origin point, a time track delineation of past and present dewpoint and dry bulb temperatures both within and without the storage compartment. The present trends of such temperatures are instantly readable and simultaneously comparable thereby providing an easily recognizable forecast of possible future sweat producing conditions (if any), and enabling advance remedial action to betaken where required.

One of the serious defects with prior art methods vand systems for controlling atmospheric conditions in storage compartments has been the necessity to compute certain of the temperature values, such as dewpoint, by means of lengthy and tedious calculations which usually are based on information which is stale by the time the computation is made. Dewpoint values within and without the storage compartment have in the past been calculated by determining any two of the following three factors: relative humidity, wet bulb temperature, and `dry bulb temperature. The determination of relative humidity has not been entirely satisfactory in the past because of the lack of reliability of the hygroscopic material employed, such as human hair, animal or vegetable libre. Likewise the determination of wet bulb temperature, particularly aboard ship, has been subject to error due to difiiculties, such as' saltV incrustation. The present invention employs, preferably but not necessarily, dewpoint sensing means Zknown as Dewcell Patent No. 2,359,278, which device provides an accurate dewpoint indication. Further with respect to the control of atmospheric conditions in the Yholds of ships, it has been the practice in the past to obtain at least two of the aforementioned three basic factors for computing dew? point, only a few times a day, perhaps two or three. Usually such basic factors are obtained and computations made irregularly and in an untimely manner.

ln View of the fact that temperature within a storage advance remedial action,

methods and apparatus in this field.

as disclosed in United States Yindicating what F 2,822,743 Patented Feb. l1, 1958 compartment or the temperature of the outside atmosphere may change a substantial amount, for example, 40 in one hour, particularly with respect to a moving ship at sea, highly detrimental atmospheric conditions may exist within a cargo hold of such ship for some timeV Furthermore, methods and apparatus heretofore suggested to meet this problem have failed to provide suitable or timely prognostication of atmospheric conditions within a storage compartment or within the several holds of a ship. Nor has such prior art provided means for notto do with respect to ventilation or,recirculation of lair in a storage compartment. In addition to this, as aforementioned, it is usual for the last known atmospheric conditions within the storage compartments to be several hours behind present conditions due to thetediousformer procedures to obtain the basic aerological readings, the necessary psychrometric conversions and the like. Furthermore, skilled personnel have been required vinthe past to determine the aforementioned aerological factors. Such personnel of necessity have to have some knowledge of aerology of the climate in the hold and some knowledge of psychrometry. A

One of the objects of the present invention is to overcome the above dilicuties.

The invention in one aspect thereof comprises a system having in combination means for sensing the dewpoint temperatures and the dry bulb temperatures both within and without a storage compartment to which are operatively connected means for delineating upon a common surface and with respect to a single graph having a common origin point, a plurality of tracks, each in response to its respective temperature. Means are provided for moving such delineation meansand surface with respect to one another in response to the passage of time, such temperatures thereby being shown whereby the latest delineated portions of the tracks (the track heads) are shown in accurate relative positions at any selected time, such delineating means thereby showing a continuous time record of the temperatures sensed by the sensing means. There is thus given an indication of past and present relations of such temperatures and the trends thereof whereby a prognostication of future atmospheric conditions within the compartment can be presently and instantaneously made.

The invention in another aspect thereof is constituted by a novel method for controlling atmospheric conditions within a storage compartment, including the delineation upon a surface, and with respect to a single graph (having a single or common origin point for all measured factors), of tracks respectively representing weather dry bulb temperature (T), weather dewpoint temperature (W), and compartment (or hold) dewpoint temperature (H), and recirculatng within such compartment the atmosphere therein or alternatively Ventilating suchrcompartment with outside atmosphere, such recirculation or ventilation being with or without the introduction of de- Y side atmosphere has a higher dewpoint temperature (W) and thus is wetter and more liable to produce sweat. When such track head (H) is between the other two tracks (W and T), the compartment is ventilated with air from the outside atmosphere because the latter is lower in dewpoint temperature. In response vto such track head (H) approaching from below (in temperature value) the track (W) of the weather dewpoint temperature, dry air may be introduced into such compartment, if desired, for preventing the crossing of such tracks (H and W), and if such crossing occurs, such recirculation is terminated and the aforementioned ventilation with outside atmosphere is initiated with or without vthe introduction ,of dry air. If such track head of the hold dewpweintvtrack (H) approachesfrom below the track (T )l ofthevwea'th'er dry bulb vtenfiperature (theY latter usually, being substantially equal .to theterrmeartureV of rthe compartments internal surfaces), aneimmediate prognostication,ofisweat upon the internal surfaces of thecompartrnentcan be made and as much. dry air should be introduced into Ysuch compartment as is available to prevent the occurrence of fsuch compartment sweat. The aforementioned introductiony of dry air should be accompanied byventilation of the compartment with the outside atmosphere because its dewpoint is lower. Should said track head of the compartment dewpoint H) be discovered above both of theother twok tracks (T and W) sweating is taking place andl again dry air should be introduced into such compartment in as large a volume as is available, together with initiation of ventilationrof such Vcompartment thereby to bring such track head (1 -l) below, (in value) the weatherdryv bulb temperature track (T).

Various, further and more specific objects, features andadvantages ofnthe invention will clearly appear from the detailed description given below taken in connection with the accompanying drawings which form a part of this specitieation and, illustrate, by way of example, preferred methodsrand arrangemrnents of apparatus for carrying.

out the invention. The invention consists in such novel methods and combinations of features ad method steps as may be shown and described in connection with the apparatus herein disclosed.

ln the drawings:

Fig. 1 is a schematic-representation of one form of system embodyingothe'present invention and including, in schematic illustration, a longitudinal section of a ships hold;

Fig. 2 is a `sectionalview taken substantially on line 2-2 of Fig. l; v

Fig. 3 is a perspectveview, oo an enlarged scale,vof. a scroll or strip charthavingvdelineated thereupon a plurality of tracks with roteren/certo as ingle graph, the varying magnitudes represented by the tracks being delineated with respect to a singlettemperature coordinate and a single time coordinatesuchtracks .providing a continuous time record of the selected temperatureconditions, such conditions being delineated particularly with respect'to the control of ship sweat (condensation upon the internal surfaces of a storage compartment);

Fig. 3a is a side view ofa preferred form of rmeans for mounting and moving a kstrip chart;

Fig. ,4 is somewhat analogousto Fig, 5, ythetracks delineated thereupon indicating a different set `of temperature conditions and being .drawn with respect tothe control of cargo sweat (condensation upon the cargo);

Fig. 5 is a perspective .View of a strip chart in the form of a scroll analogous to that shown in Figs. 3 and 4 but v employing track delineatingY means comprising a modiiicaetionrover those shown in Fig. l; and

Fig, 6 is a plan view `of a circular chart in the `form of a liatdisc upon which the aforementioned--temperature tracks are delineated with respect to polar coordinates.

by track delineating meanssubstantially similartothose shown in Fig, 5 it being understood',y however,` that the' '4. track delineating means shown in Fig. l may be employed with respect to such a circular chart.

The principles of operation upon which the present invention are based will now briey be set forth, after which the method and apparatus will be described. This description relates the invention to `operation aboard ship, particularly of the cargo carrying variety, although the invention is not limited thereto, it being applicable to control of certain,,atmosphericconditions in anycompartmerli.

'the air, as is well known, has the ability to pick up or release moisture. The amount of moisture that can be carried by the` air is not constant but varies with its temperature; that is, warm air can retain more moisture than cold However, at any given temperature there is a limit tothe amount of moisture the air can retain. When the air contains the maximum amount of moisture at any given temperature,- it is said to be saturated and itis at its dewpoint temperature; At ,any condition 4belowsaturation, when the air does not contain all that it could for that temperature, its moisture content is indicated by the term percentage of relative. humidity which is the percentage of saturation.

The Y control of ship-sweat .and cargo sweat problems istn intimately related to the temperature of the air` and the amount ,of moisture that .the air can retain, the reason being thatras air is cooled, .the amount of moisture that itcan retain becomes less.. Thus if the moist-ure content of a given volume of air does not change, its relative humidity will rise asthe temperature falls. If the temperature is lowered sufliciently, .the relative humidity will Y rise to and the air will become saturated, thereafter producing acondensation as the .temperature further falls. The temperature yin ,degrees at which the airv becomes so saturated and below. which it has to give up some of its moisture (asa, condensation), of course, comprises the dewpointI of theair.

Thuswhen a sample of air. is cooled to Aa certain temperature, the relativehumidity will reach 100% and the air, as aforementioned, becomes saturated. Further, if the air ,is cooled below .this temperature, the excess moisture will be condensed usually in the formof a dew. Such dew comprises the aforementioned sweat. The latter consequentlyis nothing l,more than the condensate formed because the airin contact with a cold surface was cooled below its `dewpoint. Ifthe ships structure is the surface, ship sweat forms. If the cargo provides the surface, the ,condensation is cargo sweat.

ifjthe temperature of` any object in the hold, includingrthe cargo or'the structure, is below the dewpoint temperature of: the, hold, air .in contact therewith, sweat willjform on suchobject. For .this reason, under many conditions, litis wrong to ventilate the .holdwith outside aii'.VV Furtherrnore,,some Acargoes are hygroscopic, that is, the cargo may `absorb vmoisture from or. release ymoisture to the ,hold air. Consequently the relative humidity of theliold air changes continually.

In. order to be apprised ,of the pertinent atmospheric conditions within ,thelhold .there should be considered the type vand,temperature, of `the cargo, the `temperature of the, structure andthefdewpoint of the hold air. The temperaturefe theupper ship Ystructurezis usually substantially the same as thedry bulb temperature (W) of the outside air.

Since. itI .is impractical to control -the temperature of the cargo or of the;sh i p sjstructure, ship 'sweat andcargo sweat may Yebencontrolled by controlling .the .dewpoint of the-hold air #,(Hyand maintainingA the .same Yata safe level. This Lisaaceomplished by employing:Y

(1) Ventilation means,`- thaty is, meansfor supplying-and distributing-aic-frorn the outside atmosphere- (weather air);to. the holds, The ,term ventilation as employed sagem enables the initiation of the aforementioned remeclial'acl` tion well'inv advance of the occurrence of damaging conditions, the apparatus, as aforementioned, can be of substantially lower capacity than has been heretofore required it is preferably mixed inwith a current of the ventilation l or recirculation air. However, the system is capable of introducing dry air alone to a hold in the absence of either ventilation or recirculation.

(4) Instruments for sensing and recording (or indicating) the dry bulb and dewpoint temperatures (T and W) of the outside (weather) air; Athe dewpoint temperature- (H) of the hold air; the dewpoint temperature (D) of the air emanating from the dry air supply means; and the dry bulb temperature (C) of the cargo.

In summary, ship sweat will occur when the dewpoint temperature (H) of the hold air is greater than the temperature (T) of the ships hold surfaces; and cargo sweat will occur when the dewpoint temperature (H) of the hold air is greater than the dry bulb temperature (C) of the cargo surface.

In order to prevent ship after it has occurred):

(a) Ventilate the hold with outside air if W (the dewpoint temperature of such outside air) is less than H (the dewpoint temperature of the hold air); or

(b) Recirculate the hold air, usually with the addition of dry air, when H is less than W.

sweat (or dry out such sweat -In order to prevent cargo sweat or dry out such sweat4 after it has occurred) (a) Ventilate the hold with or without the addition of dry air when the temperature (C) of the cargo is greater than the dewpoint temperature (W) of the outside air. Ventilation Ican be done except in rough weather when it usually becomes mandatory to recirculate the hold atmosphere therein with or without the addition of dry air; or

(b) Recirculate the hold air when the temperature (C) of the cargo is less than the dewpoint temperature (W) of the outside air. In this condition the weather air is eX- cluded and such recirculation can be made with or without the addition of dry air.

Application of the above principles will prevent the formation of ship and/or cargo sweat and are applicable with respect to ships (or other storage compartments) which are fitted with the aforementioned recirculation and ventilation means.

In addition to drying out such sweat after it has occurred, it is extremely important, particularly concerning certain perishable cargoes, to know in advance the trends of atmospheric conditions which will in the future produce ship and/or cargo sweat whereby remedial action may be taken well in advance of the proposed occurrence of the damaging conditions. The present invention is particularly concerned with methods and means for controlling atmospheric conditions in ship holds or other storage compartments wherein such dangerous conditions are forecast by easily and instantaneously readable means and such advance remedial action can be taken. By means of the present invention it is possible to know what is going to occur atmospherically within a compartment in the imminent future, that is, several hours in advance. This is of substantial assistance to the operator of the system in view of the several types of conditions to which a ship is subject, namely, (a) diurnal changes, that is, daily changes in the weather normally associated with changes from night to day;I (b) sea changes resulting from, -for example, movement in and out of a warm stream, such as the Gulf Stream; and (c) other weather changes such as winds and seasons.

,also in view of the fact that the present invention because prevention requires substantially less capacity than cure The prior art methods and devices in this general field have been concerned with taking action after the event rather than before. Thus, since the present invention enables the use of apparatus of substantiallyv lower capacity, it can be also substantially less expensive, Y

smaller, and thus easier to install. v

Referring now to the drawings, one form of the system for carrying out the invention is shown in Fig. 1 which will now be described.

The hold 10 of a ship 11 is shown having means (generally indicated at 12 and 13) for Ventilating the hold and alternatively for recirculating in such hold its own` atmosphere, both means being operable with or without the addition of dry air from an air dehumidifier unit 14 to be more fully explained hereinafter.

Although only a single hold is shown in Fig. 1 (for purposes of simplicity), the invention will, be described in connection with a ship having four separate holds.

Means are provided for delineating upon a common chart'surface a plurality of time tracks of the various temperatures (dewpoint and dry bulb) whereby the operator of the system can at a glance instantly and continuously determine the conditions in the holds and is enabled to forecast within the imminent future what is going to happen therein and thus can take suitable remedial action, if necessary. Such track delineating means is schematically sho'wn in Fig. 1 and comprises illustratively: Y

(a) A thermometer 15 for sensing the dry bulb temperature of the outside atmosphere (weather dry bulb temperature)-abbreviated as T. This is -substantially equal to ship hull temperature.

(b) A humidity sensitive cell 16, such as a Dewcell," for sensing the dewpoint temperature of the outside atmosphere (weather dewpoint temperatureabbreviatedll as W);

(c) A humidity sensitive cell point temperature of the hold atmosphere (abbreviated as H or by a numeral 1, 2, 3 or 4, the numeral being selected to correspond to the number of the hold);

(d) A further humidity sensitive cell 18 for sensing the dewpoint of the dry air discharged from the air dehumidier unit 14 (abbreviated as D);

(e) A dry bulb thermometer 19 for sensing the temperature of the cargo in the hold 10 (abbreviated as C).

It will be noted that the hold 10 is provided with three decks 10a, 10b and 10c, the first central hatch openings which are covered by removable 17 for sensing the dewhatch covers 19 and 20 respectively. A weather deck 21 is provided with an aligned central hatch which is covered by a removable hatch cover is divided into three separate cargo spaces 10d, 10e and 10f. For purposes of simplicity, the description will concern itself with the cargo dry bulb temperature within the upper space 10d as sensed by the thermometer 19a. v However, thermometers for the other spaces may beY secondary cylindrical core 28, the motion being controlled in accordance with time as by a'suitable clockV means 29 which drives the scroll at` a constant rate. The

strip chart v26, is lbratesl, with reference to a. single past and present atmosphericv two having conventional 22. Thus the hold 10 A the thermometers, are l the form of a scroll which is j originally wound upon a primary cylindrical core 27 and'y which unwinds downwardly upon a spaced andparallel j @sans graphgthe vertical4 coordinate "comprising time' :and fthe eachv of'the factors which 'areto'be '.deline'atedeas tracks. uponthe chart 26:Y For example; ingthe particular form shown, there are embossed upon the periphery of"such wheel, illustratively, `the aforedescribedabbreviations W, T, Hand D, together with the .n ume'ralsl',2,"3'and 4, such numerals corresponding to the "holds bearing such numbers. The type wheel 1iscapable,under the influence of the control means 32', of 'axiallmovem'entiin the direction of the arrow 33 andradiallmovementin the direction of the arrow 34.. Furthermore,.such wheelV is4 capable vof angular movement aboutthe axis'V thereof `for the purpose of placing a selected symbol 'in position for printing upon the scroll 26, the roll 27 serving Ya backup function. It we assume, for purposes of' illustration only, that there are eight separate symbols, namely, W, T, C, D andl, 2, 3 and 4, the control means controlmeans 32 moving the type'wheel 31 to a plurality of successive positions, each-'one being characteristic of the particular sensing means temperature which is momentarily selected for recording upon the scroll:A I have found it desirable, for example, at fifteen second intervals, to sense successively thefaforementioned eight separate temperatures (dewpointand. dry bulb) and. to make characteristicmarks'upon the 'scroll foreach; Thus, for the sensing of weather dry bulbtemperature(T) theV type wheel 31 will be angularly shifted'so that 4the T is presented for printing uponthe scroll 26,' suitable inking means (not shown) being provided for the type wheel. The type wheel 31 also will be shifted axially to the proper temperature position corresponding to the weather -dry bulb temperature (T) with'resp'ectjto the' `temperature e scale Aup'on'the strip chart. WhentheY type rwheel is thus correctly positioned,`with'respect to "the stripV chart, it is moved radially from its normalposition, which is slightly removed from the chart, into temporary engagement therewith, thereby to print a T.' Thesame procedure is followed with respect to lthe printing oi all oli-the other symbols. It is evidentthat in this example "only Aone' and three-quarter minutes (7 X15) wll'sep'arate' the recording of the first symbol from the recordingjof 'the last in a single run of symbols. The type wheel'movessomewhat in a pecking motion under the'influence of the control means 32. A new run of symbolsfmay'besensed and printed commencing, vfor example,'fteen seconds after the completion of the last run,therebyv producing a two minute rinterval between successive printings of a given symbol whereby the substantially continuous tracks shown are marked upon the chart as in Figs; 3 and 4. ForV illustrative purposes the` figures do notshow suchfrequency of printing. The control means 32 comprises meansfor converting the values of the signals Afrom the dewpoint temperature sensing means to the same scale as that of the signals from the dry bulb temperature sensing means, thereby adapting such values'for'comparison with one another on a common scale. Of course, conversely the values of the signals from the dry bulb temperature sensing means can beconvertedto the `saine scale as that of the signals from the dewpoint temperatureesensingjmeans, if desired.

The aforementioned 'recirculatin'g and Venti'latingmeans will now be described.

A-primary airfduct assembly 35 is providedwhich, in the-fornr-shown in Fig. 1 ,extends substantially vertically ,32 'will provide 'eight tracks upon .the strip chart 26; Such tracks are provided-by the and is inthe forward region of such'ho-ld.' VTheprimary' air ducbassernblyv 'isdn communication with the i several cargo spaces. 10d, 10e andltlf preferablyinear hthe' topM portions "thereofbytransversely' extending A subducts 36,

`37"and 38," respectively, which', in 'themannershOWn in Fig. 2, are"providedwithoricesamidships nandat the outboard extremities ofsuch'subducts: Foriexamplegthe J subduct' isprovided 'with an amidshipf outlet'. orice at 36a'andwithoutboardY orifices, 36h and 36C.

The air Vduct assembly 35"can be placed in communication with either the'"outside atmosphere or the,r hold by means'of a damper 439'which canrbe alternatively/"posi tioned, asshown in solid lines in Fig. l, or in .broken lines; Whenin the former positionytheair duct'assembly' 35is placed in communication with 'an inletv duct lllhaving an orifice 46a inV communicatiomwith'the outside,V4 atmosf phere. It .is' through` this latter .duct that .air for. venti.-

latingpurposes isdirected Ainto thehold." Damper 39 Ais operatively connectedfto suitablefcontrol means which. preferably is situated von thebridge ofthe vessel whereby it canbeshiftedtoeither'one of the aforementioned positions; A control panel A4]; is shown having 'thereon a control forthedamper'39as will appear more fully hereinafter.Y

The aforementioned damper 39'is vpreferably situated within a suitable damper housing. 42' upon which the inlet' duct 40 i's'mounted and which housing provides communication between. the inlet of the duct assembly.' 35(at'its top) and'thehold Y10d in response to' the damper 39being moved` to` the. position vshown in brokenlines in Fig.,1.

Means for moving the air'in the primary 'air duct 35 are employed comprising a fan 43"whi'chis connected to anelectric motor 44. The fan `43"preferably is situated just beneath the damper 39. y

Ananalogous ductsrystem isf located preferably in ,the

after portion-o the' holdftl and comprises a secondaryV air ducteassembly45 having 'transversely extending :sub-

ducts46', 4and'43 which are'anal'ogousto the subducts 36, '375 and'SSrespectively.

The exhaust extremity tof 45 (at the*top thereof) can beplaced alternatively in communicationwithl an atm'ospheri'cl'exhaust '49er-'with Vthe hold libymeansofa damper. 50 which is analogously mounted ascompared'to the dampe'r39. That is, inthe form shown in Fig. l, the.damperStlican'assume the position'shownv in solid' lines'or'in broken lines. When inl the position shown in solid lines, the` exhaust extremity of the secondary Lair duct'45' is incommunica'tion with-the exhaustoutlet'zig andwhen inthe 'latter position, such exhaust .extremity is in communication withthe holdf The positions'of the 'dampers 39 and 50 are as follows: (a) The holdiltlfi's .on ventilationA when the dampers 39 and 50 are both iin .the positions shown in solid lines in Fig; l; and f (b) The 'hold is on recirculation when saiddainpcrs '39.'ancl` VStlare in their alternative positions, that is, in the positions' shown in "broken lines.

Thus when fon ventilationtheloutside atmosphericair will'be drawn into -the primary air duct 35 by thefan43 and'willbe directed via theduct and subducts to their various` outlets'and` thence aft toward the secondary air duct 45 where suchair 'willbe collected and directed under the influence oian'exhaust fanSll to the exhaustV outlet 49;. .The exhaust `fan 5I is driven by a suitable electric' motor 52;

Alternatively; when the said ducts are in the recirculation position, as Ashown in broken lines, the air' of -the holdwil'l'bef recirculated therein under the influence of .the'fans 43 and 5I." That'is, the exhaust extremity of the. secondaryl air duct 45 will be in 'communication' with tl1en upperregion'othe cargo space 10d via the' after-damper. housing 53 which delines a passage 53a.. The supplyl fan.

43, instead of being in communication with' the outer atmosphere; will -be in communication 'witlrthe forward the rsecondary duct assembly tioned control buttons.

asaefms which is defined by the aforementioned housing 42.

It will be seen that the upper cargo space d serves as a return conduit for the movement of the atmospheres taken from the lower two cargo spaces 10e and 10f during recirculation.

I have found it desirable to control the aforementioned dampers 39 and.50 by means situated on the damper control panel 41 on the bridge whereby an operator, by controlling suitable push buttons or switches upon such panel, is capable of remotely controlling the dampers to place the hold .on ventilation or on recirculation. Consequently the damper 50 is also operatively connected to the damper control panel 41, suitable push buttons 55 and 56 being respectively provided thereon for placing the dampers '39 and 50 in their recirculation and ventilation positions respectively.

I have found it'desirable to introduce dehumidified air into the system just above the supply fan 43 although it is possible to introduce it at any other 'suitable location.

Consequently a dry air inlet conduit 57 is provided having an outlet directly above such supply fan. The conduit 57 in turn is connected to a main dry air line 58 which extends fore and aft of the ship and which feeds dry air to the various other holds under circumstances analogous to those shown and described in connection with Fig. 1. The aforementioned dehumidifier unit 14 is connected via an outlet conduit 14a to the fore and aft line S8.

The dehumidifier 14 can be placed in or out of operation by control of a suitable push button or switch means,

as at 59, located, for example, on the control panel 14.

Furthermore, there may be provided in the conduit 57 a dry air damper 60 which is governable by a push button 61, also located on the panel 41.

The means for angularly shifting the various dampers above mentioned may be of any suitable type, for eX- ample, of the pneumatic variety, wherein theV control of the actuating medium is easily effected through electrically actuated devices under the influence of the aforemen-` SHIP SWEAT The novel apparatus and method will now be described with particular reference to ship sweat problems easy Yto forecast thattrack 1 is not and to Fig. 3 wherein there are delineated rupon the chart, tracks corresponding to the following:

The weather dry bulb temperature T,

The weather dewpoint temperature -W,

The dewpoint temperature of the dehumidified air -D, and

The dewpoint temperatures 1, 2, 3 and 4) of the atmosphere in the four holds of corresponding numbers.

Cargo sweat problems will be later set forth in connection with Fig. 4.

Re: Hold No. 1.-The track of the dewpoint temperature of this hold, for the time shown on the chart, is indicated by the series of numerals 1 which are printed thereupon by the apparatus described above in Fig. 1. Track 1 indicates that the dewpoint temperature of the atmosphere of hold 1 is Substantially below both the weather dewpoint temperature (W) and the weather dry bulb temperature (T)- Consequently there is no danger of ship sweat in view of the low dewpoint of the atmosphere of this hold. This is true because the weather dry bulb temperature (T) is substantially identical to the temperature of the ship itself (at least that portion above water) and thus of the bounding surfaces which define such hold or storage compartment. Thus in effect a comparison is made between the dewpoint temperature of the hold atmosphere and the dry bulb temperature of the The reason foi-'comparing track 1 with tracks W and T is for the purpose of making a decision as to whatto peraturev than Vthe Weather dry bulb temperature. Re circulation will in'surethat there are no localized 'stag` nant volumes of air'wheredewpoint temperature of such volumes rmay rise above 'the temperature of any tactile'v It would 'thus be ill advised to surface causing sweat. ventilate because this would introduce into the compartment air having a higher dewpoint temperature.v Furthermore, by observing the most recent portions (track heads) of the aforementioned three tracks (l, W andT), it is trending vtoward either of the other two, trackswhereby remedial action must be taken to stave off formation of ship sweat. Such forecast can be made for the imminent future usually embracing several hours. A., Y v

Re: Hold No. 2.'The dewpoint track of the atmosphere of hold No. 2 (track 2) indicates that from 0000 up to 1300 there should be recirculation but at 1300 a changekyshould be made to ventilation. The reasons for this are that the dewpoint temperature of the hold air is lower than that of the weather (outside) air up to 1300 and thus should be used in recirculation. However, after the'latter time the weather air becomes lower in dewpoint temperature and thus should be introduced into theVv compartment by ventilation.' The trend of these ytwo tracks can be easily determined well in advance of the crossing point 62 which thus can be easily forecastfsev-` eral hours in advance. The aforementioned recirculation and ventilation occurring in hold No. 2 can be with or without the introduction of dry air from the dehumidier 14. Y y

Re: Hold No. 3.-Track 3 starts out about 0000 be-v tween track W and track T, thus'indicating that the air in this hold is ofhigher dewpoint and wetterthanthe crosses track W at; 63. Consequently hold 3 should be started on ventilation weather air up to 0500 when track 3 that dewpoint conditions in this hold apparently, were overlooked from 0000 up to about 1100 (point 64). The day apparently was started without either ventilation or recirculation in this hold. From 0000 up to 0545 no ship I sweat occurred because the internal surfaces of the compartment (track T).were Warmer than the dewpoint Vtemperature (4) of the hold atmosphere. However, at 0545 track 4 crossed track T at point 65 and the internal surfaces of the compartment became cooler than the dewpoint of the temperature of the hold atmosphere and condensation upon such internal surfaces commenced. At

about 1115 (point64) the operator' of the system took remedial action which is reflected by a sharp decline bounding surfaces of the compartment. Since the latter surfaces are substantially warmer than the dewpoint temthereafter of track 4. An operator ofthe system, jupon at 1100 in hold 4, should `take observing such conditions the following action: Y t (a) Direct from dehumidifier unit 14 all of the dry air which can be` allocated to this hold commensurate withk the minimum needs of the other holds.

(b) Placevhold 4 on ventilation in order to take advan-K tage of the 'outside air which at this time is of considerably lower dewwinttsmrsfawrs than, that Qf @has sin.

balance ofthe time thushold 3 shouldy spaans? 11 y By 1245 (point'66) track' 4 has 'crossed'trackiTthereby 'arresting the formation Lof 'iurthershipA "sweat attbis time and thereby initiating the drying out. -of"the"*sweat already formed in hold 4. Subsequent to'point' 66, the sweat already formed in hold 4 .willbedried `out -and removed.

if we assume that'track C des`ignates"cargo"dry Abulb temperature of the cargo inhold "4,itis seen fromthe relative position ofthe tracks C"and"4v thatcondensationupon the cargo will have existed'since 0000 up to "1400 (point 67) where track 4 crosses track C and the dewpoint temperature of the atmosphere of 'hold' 4 Ybecomes lower than the dry bulb vtemperature of the cargo. That is, the formation of cargo sweat will'cease at point 67 and CARGO SWEAT Referring now to Fig. 4, the invention will be described with respect to certain cargo sweat problems in the several holds.

Althoughtwo chartsare shown in the drawings (Figs. 3 and 4), only one chart is normally employed in this invention. The purpose ofthe chart shown in Fig. v4 is to emphasize the aforementioned several cargo sweat situations which may occur in the several holds. The symbolsY employed for delineating the several tracks of Fig. 4 are similar to and have similar meanings to those shown in Fig. 3.

In Fig. 4 only a single cargo temperature track is shown whereas in actuality there would be a plurality of Vsuch tracks, at least one for each hold. If a given hold .is divided into three separate spaces, as shown inFig. 1, there may be three cargo temperature tracks for each particular hold. However, for simplicity only a single cargo temperature track isshown in Fig; 4 which will suflice for thedescription of the severalproblems set forth below. Thus the single cargo temperature track is illustrative of and applicable toany cargo compartment.V

Re.' Hold No. 1.--lt should be noted thatwhile the cargo temperaturetrack .(C)of Fig. 3 indicates that the cargo was initiallyat 88 F.' and thus was presumably loaded warm, thecargotrack'shown in Fig. V4 indicates that the cargo temperature at 0000 was about F. and presumably was loaded in cooler weather.

Regarding hold 1V (Fig. 4), during-the time-shown (0000-1700), the .cargo dry bulb temperature (C.) issubstantially greatenthan the dewpoint temperature of the atmosphere of hold 1. Consequently no action need be taken with respect to hold No. 1, that is, Vthe-,operatorA of the system canmaintainwhatever condition exists with respect to recirculation or ventilation so far as cargo sweat is concerned. It appears that recirculation for hold No. 1 is a more desirable course because the dewpoint temperature of the atmosphere of hold No. 1 is lower than that of the weather air. Thus no good purpose would be served in reducing the dryness of the atmosphere of hold No. 1 by Ventilating same. with outside air. There is no danger of ship sweat in hold No. 1 in view of the greater warmth of the compartments bounding surfaces as delineated by track T. The trend of the head of track 1 (the most recent portion thereof) with respect to the heads of` tracks C and T indicates no imminent danger of ship or cargo sweat.

, Re: Hold No. 2.-Track 2 indicates thatthe` .dewpoint temperature of the atmosphere of hold'No. 2 from 0000 up to about 0945' 'is .somewhat greater than the dewpoint temperature'of; the weather air (track W). Thus during this'tmehold No. 2k shouldb'e 'onventilation preferabty with theaddition of dry air; However; ate'about. 0945"v track 2`crosses track W and 'the'dewpoint temperature'of the hold 2' atmosphere becomesV llower than' that 'of the weather. air and'thus after0945 hold 2 should Vbe'onrecir.-

'culation'preferably with the addition of dry air until the situation changes, at which time the aforementioned prin` ciples should be applied. Thus the operator of the system willsactuate the pertinent control buttons 'uponthepanel 41 (Fig. l) and will maintain ventilation during theperiod vaforementioned (0000 to 0945) and will discontinue same and actuate the recirculation-button 5S about 0945, the dehumidifier unit'14 preferably being in operation during.`

all of "this time.

An' observation of the' track'head ofv trackzZ and'of track'C throughout theperiodV set forth in Fig. 4 indicates that at no time is thereV imminent dangerofthe cargo.

becoming coolerv than the .dewpointtemperature ofthe hold air'and thus the danger of cargo'sweat does not exist during" this period;y

although there was no cargo sweat, the trend of the heads of tracl `"3'and track'C indicates the imminence of such sweat; However, it appearsthat no remedial action was taken in the light of such trend.` At point 68 track 3 crosses track C and the dewpoint temperature of the hold 3 atmosphere then becomes higher than the temperature of the cargo (until about 0245). Consequently cargo sweatwill'occur'between` about 0035 and 0245. At about? 0130 (point 69) some remedial action was taken for the purpose of depressing the Vdewpoint temperature of the hold 3 atmosphere below the Vdry bulb temperature (C) ofthe cargo. This remedial action consisted of placing hold-3 on ventilation and addingdry air thereto from the dehumidifier unit 14, this being accomplished by operatingv the pertinent control buttons upon the control panel 41A or by suitable manual operation. Itis understood that although the control panel 41 indicates connections to the several dampers and motors only of hold No. 4, analogous controls are provided for all of the other holds. Of course, only a single c-ontrol is provided for the dehumidi- "tier unit 14. It should be noted that the several dampers shown in Fig. 1 with respect to hold No. 4 may be conor locally at the location of the damper itself, for example, by manual means.

Reverting to point 69 of track 3,' an observation of this pointin comparison with a substantially concurrent point upon the track W indicates the desirability of placing the compartment on ventilation because the weather air lat this time (0130) lis substantially lower in dewpoint temperature than that of the hold air. As much dry air as is available. from the dehumidifier unit should be directed intoholdFNo. 3 for the purpose of depressing the dewpoint temperature of hold No. 3 atmosphere commencing atpoint 69. Such introduction of dry air, of course, must. be commensurate with the 'minimum needs of .the other holds. i itis, ofmcourse, possible to remedy the situationexisting at (01.30) `in hold No. 3' without the addition of dry air because the aforementioned ventilating of 'this hold will eventuallyA accomplish the desired "purpose but substantially more slowly than if dry air No. 3.' Thus such ventilation 'should continue until about 0430 (point 71) at which time4 hold No. 3 should be Re:'Hold No. 3.-No particular problems 'are presented The aforementioned venassegna changed from ventilation to recirculation. In view of the conditions existing in hold No. 3 from 0430 to the end of the time shown, recirculation should be continued, there being no trend indicated which forecasts either cargo sweat or ship sweat. The injection of dry air into hold No. 3 and the recirculation of its atmosphere normally would be continued until the sweat previously deposited on the cargo was fully dried out.

Re: Hold No. 4.-The remarks above given for hold No. 1 are also applicable to hold No. 4.

Re: Uniform cargo temperature track.-In lieu of the aforedescribed method and means for controlling the hold atmosphere to prevent cargo sweat, reference being had to track C (cargo dry bulb temperature-variable), I have found it more economical and desirable though to a lesser degree to delineate upon the chart 26 a steady dry bulb temperature track 72 by means of a relatively xed but manualy adjustable pen 73 (Fig. 4) which is manually positioned to mark a steady track of the dry bulb temperature of the port where the cargo was loaded or of the temperature of the warehouse where the cargo was stored just before loading. It is normal for a cargo vessel, of course, to take on numerous` parcels of cargo, each one being loaded at a different port and at a different temperature. Consequently it is wise to mark track 72 at a temperature corresponding to the parcel which is most likely to be subject to cargo sweat, for example, the parcel having the lowest dry bulb temperature. Also it is within the scope of the invention to mark a plurality of such tracks, each one indicating the temperature of the place where a parcel of cargo was loaded.

It is considered good practice to mark a single steady track for each of the holds, each track indicating the coolest parcel of cargo in its respective hold. Consequently, if such coolest parcel were prevented from sweating, the other parcels would be protected.

In Fig. 4 the steady track 72 indicates, for example, a uniform temperature of about 57 and if, for illustration only, we assume that this is the temperature of the coolest parcel in any of the holds 1, 2 or 4, there is no danger of cargo sweat forming upon such parcel because it is at all times warmer than the dewpoint temperature ofthe atmosphere in the holds 1, 2 and 4. However, if we assume illustratively that it is the temperature of a cargo parcel in hold 3, a trend toward cargo sweat producing conditions (for each parcel) is seen between 0000 and about 0110 with such sweat forming upon such parcel commencing at the latter time and persisting until about 0200. The aforedescribed remedial action which occurred at point 69 is applicable with respect to the steady track 72.

It is within the purview of the invention to employ a steady dry bulb temperature track 72 of one cargo parcel in combination with track C (Fig. 4) indicating the varying dry bulb temperature of a parcel of cargo.

Re.' Trend of track W with respect to track C.-The rule should be borne in mind: Never ventilate a hold when the weather track W rises above the cargo track C or track 72). When the weather dewpoint temperature W rises above the cargo dry bulb temperature C, it is clear that cargo sweat will occur if the hold is ventilated with weather air. Consequently recirculation is indicated during such condition. In Fig. 4, commencing at about 1230 (point 74) weather dewpoint temperature (W) rises above the cargo dewpoint temperature (C) and recirculation should be employed 1n the pertinent holds in view of the fact that tracks 1-4, inclusive, indicate lower dewpoint temperatures than that of the weather air (W). If, for economy, there are no tracks C but only track 72, then recirculation should be commenced no later than 1030 according to Fig. 4. Of course, it is conceivable that a hold atmosphere track head might indicate a higher hold dewpoint temperature than that of the weather air whereupon it would be preferable to ventilate instead of recirculate,

the latter comprising the only exception to the aforementioned rule that the hold should never be ventilated whenl cylindrical core 27 and being wound upon a secondary i cylindrical core 28 without any intervening r'olls for moving same, it has been found desirable to position such cores 27 and 28 as shown in Fig. 3a and to pass the'scroll 26 over a toothed time roll` 75 which preferably is positioned immediately beneath the type wheel 31. Suitable teeth or short studs 76 are positioned around the periphery of the time roll 75 at each extremity thereof, the studs engaging perforations 26a (Fig. 3) in the scroll 26. Suitable means may be employed for imposing a relatively small drag (in the direction of arrow 27a) upon the core 27 and a pull (in the direction arrow 28a) upon the core 28, the accurate timing of the movement of the scroll being under the inuence of a time motor 75a which drives the time roll 75.

Referring now to Fig. 5, there are shown means for delineatmg the several tracks by continuous or uninterrupted lines as compared to the means shown in Fig. 1. The means for mounting the scroll 26 are identical to that described above in connection With Fig. 3a.

A plurality of pens 77, 78, 79 and 80 are employed which are respectively mounted upon stylus arms 81, 82, 83 and 84. Such arms are concentrically mounted, as shown generally at 85, the arm 81 being secured to a central shaft 86 and the remaining three arms being respectively secured to concentric sleeves 87, 88 and 89. Such shaft 86 and concentric sleeves 87, 88 Vand 89 are operatively connected to a stylus or track control means 90 which is analogous in function to the control means 32 of Fig. 1, such shaft 86 and concentric sleeves being angularly shifted respectively in response to C, T, W and l thereby to produce continuous tracks showing the dry bulb and dewpoint temperatures which such symbols signify as above set forth. Such continuous tracks are distinguished preferably by using different colored inks.

In view of the concentrically mounted shaft and sleeves 85, the transversely extending lines upon the scroll 26 are arcuate and of appropriate radius.

Situated behind the scroll 26 and pens 77-80 is a suitable backup surface member 91.

Although in Fig. 5 there appears to be a substantial distance between the tip of pen 77 and that of pen when such pens are in alignment, such pens may be constructed to be substantially nearer together, the drawing being for illustration only. It would appear from the drawing that such pens 77 and 80 are separated by about 45 minutes as measured upon the time scale at the left 0f the scroll. However, this is substantially less in a full scale model of the device. As a practical matter, such pens may be separated to the degree shown without an undue handicap to the proper operation of the system, the trends of the various tracks lbeing readily apparent.

In lieu of the scroll or strip chart shown in Figs. 1, 3, 4 and 5, it is possible to employ a circle chart 92 (Fig. 6) in the form of a Hat disc which rotates about its center, there being suitable polar type coordinates thereupon. However, it should be noted that it is not an essential element of the invention that either the time or the temperature coordinates be actually shown upon any of the charts. the trends and relative positions of the tracks being the important subject of observation. In

Fig. 6 the concentrcmountingtsztFig. 'Smay be etn- Y Such tracks cross atl 15 ployed' having' the stylus arms 81-84seeu're'd theretoV as abovedes'cribed, thepens 77-80 thereof being 'provided for marking'the several tracks upon theci'rclechart'92. The latter chart is mounted upon a suitable rotatable member which is angularly shiftable in response to time thereby providing the circumferential tirriecoordina'te. The radial coordinate is graduated'in'accordancewith 'the temperature, in the form shown, from Dto 130 F. the chart of Fig'. 6 is adapted 4for twenty-tour hot'irn'ise.4

The novel method and apparatus settorth herein can be employed on ships or in storage-'compartments-without an' air dehumidier unit to -feed dry airfinto 'the'compartm'ent. assist in preventing ill judged timingofver'1tilation or recirculation.

This invention can be employed on ships i (a) With only natural ventilation means,l that is,venti lation dependent upon the relative speed of'th'e surround'- ing atmosphere over the ship;

(b) With mechanical (power fan actu tion means, or n (c) With mechanical ventilation means plus recircnla tion means,

(d) Having a dehumidiiier unit which will providedry air for either (a) or (b) or (c).

From the above it will be seen that regardingship sweat, the two critical reference tracks are:

(o) Track W (weather dewpoint temperature) .and

(b)'1rack T (weather dry bulb temperature), the latter being 'substantially the same as the temperature ot' the internal surfaces of the storage compartment.

The position of'a particular hold trackv wit'hrespect to (a) and (b) above is the determining factor of operation regarding shiprsweat, that is, whether such hold track is:

(l) Below both;

(2) Between the two;

(3) Approaching either; or

(4) Above both.

Regardingcargo sweat, the two critical tracksare W and C as compared to the position of the hold track.

Although' the invention has Vbeen described YVin connection with ship holds and with respect to the atmosphere I as the principal gaseous medium, the inventionis notv limited-thereto For example, itis possible to apply Athe conceptlof' the invention to the aqueous' dewpoint-.of gases other' than the atmosphere. Ga's'eous substances other than air -have dewpoint temperatures andthe present invention can'be'applied tothe` controlling of sweat conditionswhen such other gaseous substances are involved.I Furthermore, the various tracks heretofore described delineatingthe dewp'oint temperature ofthe atmospheres of a plurality of holdsl may, in lieu thereof, represent several phases of dewp'oint within a single compartment.

One of the important Yfeatures of the present invention is concerned with the fact that dehumidier apparatus used aboard ship are rationed as to their power consumption. Any device which is extravagant in power consumption is undesirable for marine us'e. Consequently since the novel method and apparatus enables the forecasting Wellin advance of hold atmospheric conditions' dangerous to cargo, it is possible to take remedial action at a ltime' when minimum power' consumption will be needed for such remedial action. Thus the prognosticating aspect of the invention permits the employment of smaller apparatus of substantially lower expense in manu-- facture and oflowerenergy 'consumption (steam, electricity, cooling'water) as compared to prior art devices lacking the prognostica'tingf characteristic. l ,Y

I have found' it desirable; in addition to employing the symbols shown'n Figs. 3 and 4 for delineating the several tracks, to print"`sueh'ftrwaeks"'eaehin a distinctive color.

For example, track( C', T,' W and`D myfbe' respectively printed in blue; red, 'purple `and"yellow"`ink 'and the" several Vholdetraclrs may' beprinted in aY commonc'olor,

In the Vlatter case the inventionY will 'greatlyl ated) ventilafor example, green'. This facilitates the instruction of unskilled personnel. It` is`easy for such personnel to carry out, for'example, the following instructions:

(a) Reeicnlate' the `atmosphere in a hold whenever its green track'hea'd (hold dewpoint temperature) is to the left of 'thepnr'ple track head W;

(b) Ventilate 'a hold wheneverA its green track head is to the-right of the purple track head (W);

(c) Stich''recirculation4 Caribe with or without the addition of dry air from `the dehumidifier unit but is preferably withI Such 'ventilationis preferably with the addition of suc'hnryf'air biitrnay' be Ywithout it if dry airis unavailable;

(d) When the green track head of a hold is to the right of the red traek'head (T) (weather dry bulb temperature), air-from the dehumidifier unit should be introduced'in"th largest quantity available commensurate with the minimum needs' of the other holds concurrently with'ventilation with the lowerdewpoint weather air. If'sch dyair'is notavailable, then ventilate vigorously with the weather air alone.

Although the above described method and apparatus has been directed Vlargely tothe prevention of-sweat upon the internal' surfaces -of the cargo compartment or upon the cargditself `by` dewpointl control, it is within the purview of t` heinvention to control the dewpoint to induce artiiiciallythe deposition of sweat upon the cargo where this is desirable.y Also, it is sometimes desirable to pro-vide'ahigh relative' humidity or high Vaqueous vapor pressure, 'or high dewpoinn'for such cargoes as raw sugar or'fruit or meats'. The invention also is applicable to control dewpoint'conditions to induce vsweat within a compartr'rie'ngenerally where desired. V

Although the apparatus v'disclosed in Fig. 1 discloses the invention as applied to they hold of a ship having three superposed Aseparate chambersfit is understood that the invention is not limited thereto, it being applicable to a storage compartment having but a single storage chamber wherein recirculation of the compartment atmosphere can be through any suitable means, for example, by a conduitI within or-without the storagecompartment. Alternatively, it is possible to eliminate such a recirculation conduit and tov employ any suitable means which effects recirculation of the atmosphere within the compartment. A

The inventionisv applicable to ship holds (or other storage compartments) which are ventilated by either forced or natural ventilation, the former referring to ventilation by powered 'means suchas a fanland Vthe latter -to ventilation as caused, for example, by the relative movement between a ship (or compartment) and the surrounding air. For example, a ship moving into the wind can 'induce stronginatural ventilation of its holds. The

normal procedure for best'natural ventilation is to trim the mouth of the inlet ventilator toward the apparent' wind and to trim the mouth of the outlet ventilator away from the apparent wind.

The practice o f the invention also prevents corrosion of internalfsurfaces of storage compartments, for example in tankers,-which mayvencounter moisture.

While the Vinventionhas beenV described with respect to certain preferredA examples-which have given satisfactory results, it will be 'understood by those skilled in the art, after understanding the invention, that Various changes I and modicationsmay beY made without departing from thespirit-and 'scope'of th'ewinvention and it is intended therefore in the-appended claims to cover all such changes' andl modi'ca'tion's;

What is l 'claimed'` is z l.. AlnanairA eonditionin'gsys'tem'4 for use in the storage ofelgoodsiinlavstoreroom,sueltas the holdl of a ship,

where *the airrofl the-storeroomeand the goods thereinY are conditioned by means'of such' air conditioning system, the 'latter being of the class'including" storeroom ventilation means for mixing `outer air into thestoreroom air or replacingsuch storeroomV air entirely-'by outer air, or recirculation means for recirculating the'air ofthe vstreroorn therein, such air conditioning' system including means for-sensing the drybulb temperature (T) of the outer air, and means-for sensing the dewpoint temperature (W) ofthev outer air, the combination with lsuch sensing means-of means for sensing the dewpoint telnperature (H) of the air in 'the-stor`eroom, each such means for-sensing such dewpointtemperatures comprising apparatus responsive to the quantity of moisture present in the air, and means-for producing signals responsive to such quantity of moisture and which are functionsk of the dewpoint of such air and for acting on said signals to cause same to represent its respective dewpoint temperature (H) or (W), such means for sensing such drly bulb-temperature being operatively connected to lmeans idr producingsignals-responsive to' suchst'emp'eratur'e,4 the means for sensingandv producing signals responsive to suchdry bulb temperatures' comprising one set of means and the means for sensing and producing signals representative of such dewpoint temperatures comprising a separate set of means, means for converting the values of the signals from one of such sets of means to the same scale as that of the signals from the other set of such means, thereby adapting all such values for comparison with respect to a common scale, such several means for sensing temperatures and producing signals including such signal value converting means being operatively connected to means for recording such signals upon a common surface having a common point of origin and a common system of coordinates, namely, a time coordinate and a temperature coordinate, whereby such signals appear as a series of lines or curves upon such surface having such common point of origin and such common system of coordinates, and further whereby such lines or curves comprise in a single graph a record adapted for the act of rapid evaluating and forecasting of the atmospheric conditions in the storeroom by personnel with no knowledge of aerology and psychrometry so that said air conditioning system can be regulated by such personnel in accordance with the trends of such lines or curves in relation to each other.

2. In an air conditioning system in accordance with claim 1, such system including air dehumidifier means, means in such system so constructed and arranged that such recirculation or replacing of the air of the storeroom can be with or without the addition of dried air from such dehumidifier means, the combination therewith of means for sensing the dewpoint temperature (D) of the dried air of such dehumidifier means, such latter dewpoint sensing means also comprising the apparatus as defined in said claim.

3. In an air conditioning system adapted for use in conditioning air in a storeroom for the storage of goods, such as the hold of a shi such system being of the class including storeroom ventilation means for mixing outer air into the storeroom air or replacing such storeroom air entirely by outer air, or recirculation means for recirculating the air of the storeroom therein, such system including means for sensing the dewpoint temperature (W) of the outer air, the combination therewith of means for sensing the dry bulb temperature (C) of the goods, primary means for producing signals representative of such dry bulb temperature, means for sensing the dewpoint temperature (H) of the air in the storeroom, secondary means for producing signals responsive to respective of said dewpoint temperatures, means for converting the values of the signals from one of such signal producing means to the same scale as that of the signals from the other signal producing means, thereby adapting all such values for comparison with one another with respect to a common scale, and means for recording upon a common recording surface marks representative of said respectiie* signalslfwherebyf-allofl such temperatures are represented-each byfa respective line or curve formed'by a series' of such marks andV having-a common pointof origl and-Yafcomino'n sys'ten'il of coordinates,- namel-y, a time coordinate andaternperatnre coordinate,whereby such flinessor curves presentarec'ord'permitting rapid evaltiat-ionl of the relative trends offsueh lines and Vconsequently' the` forecasting/of theY atmospheric conditions needing .adjustment-inl they storeroom-.-

4. In a controll system for! ai'i` conditioning' means-'of the classincluding'lv'entilation means frasto'reroom for miXingoutef'lair with thestorerom air or replacing-the storeroom Iair.enti-rie'zly'by such-'outer air,- o'r means for recirculating the air of? the storeroom, with or without the addition of dried airfrom` air dehumidifier means of such air conditioning'n1eans`,-whereby the air of such storeroom yand also the goodsv therein are conditioned, the f combination f therewith" 'ofy aL prima-ry set of temperature' sensing andy signal producing* meanslv embracing means-,for 1' sen'singlh andi producing signals representative of the dry bulb temperature (C) of such goods, and a secondary set of means for sensing and producing signals representative of dewpoint temperatures and embracing: means yfor sensing and producing signals representative of the dewpoint temperature of the outer air (W) and such means for the dewpoint temperature (H) of the air of the storeroom and the dewpoint temperature (D) of the air emitted from said dehumidifier means, means for converting the values of t-he signals of one of said sets of temperature sensing and signal producing means to the same scale as that of the values of the signals from the other `set of such means, a recording surface, means for continually advancing the latter, and means for recording all of such signals upon such surface, such signals all appearing as a series of lines or curves with a common point of origin and a common system of coordinates, namely, a time coordinate and a temperature coordinate.

5. In an air conditioning system of the class including ventilation means for a storeroom for mixing into the air of the storeroom air from outside the storeroom or replacing such storeroom air entirely by such outside air, or means for recirculating therein the air of the storeroom, the combination therewith of a first set of temperature sensing means embracing means for sensing the dry bulb temperature (T) of the outer air and the dry bulb temperature (C) of the goods; and a second set of temperature sensing means embracing means for sensing the dewpoint temperature (W) of the outer air, and means for sensing the dewpoint temperature (H) of the air in the storeroom; means operatively connected to each of such sensing means for producing signals responsive to each of such temperatures, means for -acting upon the signals from the latter means connected to one of said sets of temperature sensing means for converting the values thereof to the same scale as that of the values of the signals from said signal producing means connected to such other set of sensing means, and means responsive to such signals for recording marks representative of said sensed temperatures upon a common recording surface whereby all of such temperatures will appear as a series of lines or curves formed by such marks in a single graph with a common point of origin and a common system of coordinates, namely, a time coordinate and a temperature coordinate, whereby such lines or curves present on such single graph a record permitting rapid evaluating and forecasting of the atmospheric conditions in the storeroom in accordance with the trends of such lines or curves in relation to each other.

6. In an air conditioning system of the class wherein air dehumidifier means are employed, such system being for use in conditioning the air in a storeroom for the storage of goods, such as the hold of a ship, such system including means for ventilation of the storeroom by mixing with the air therein air from outside the storeroom 19 or replacing the storeroom kair entirely by suchoutside air, or means for recirculating therein the air of the storeroom, in all cases with or without the addition of dried air from such air dehumidier means, the combination therewith `of a rst set of temperature sensing means embracing means for sensing the dry bulb temperature (T) of the outer air and the dry bulb temperature (C) of the goods; and a second set of temperature sensing means embracing means for sensing the dewpoint temperature (W) of the outer air, means for sensing the dewpoint temperature (H) of the air in the storeroorn, and means for sensing the dewpoint temperature (D) of the air emitted by said air dehumidifier means; means for producing signals responsive to each of such temperatures, means for acting upon the signals from one of said sets of temperature sensing means for converting the values thereof to the same scale as that of the signals from such other set of sensing means, thereby adapting all such signals andsvalues for comparison with one another with respect to a common scale, and means responsive -to such signals for recording marks representative of said sensed temperatures upon a common recording surface whereby all of such temperatures will appear as a series of lines or curves in a single graph with a common point of origin and a common system of coordinates, namely, a time coordinate and a temperature coordinate, whereby `such lines or curves present on such single graph a record References Cited in the tile of this patent UNITED STATES PATENTS 2,160,831 Colby et al. June 6, 1939 2,528,018 Stewart Oct. 31, 1950 2,542,944 Rieber Feb. 20, 1951 2,554,440 Coburn May 22, 1951 

